A soil borne fungus which infects the leaves of dandelions (Taraxacum officinale agg.). It is a member of the Class Chytridomycete, one the simplest and most primitive Eumycota, or true fungi.

References: 
Ellis, M.B. & Ellis, J.P (1997 new enlarged edition) Microfungi on Land Plants: An Identification Handbook.
Redfern, M. & Shirley, P. (2011) British Plant Galls.